Surveyor&#39;s rod.



o. LOGASA. I SURVEYORS ROD. APPLiCATlON FILED MAY 3. l9 l7- Patented Dec. 4,1917.

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I CHARLES LOGASA, OF WASHINGTON, DISTRICT OF COLUMBIA.

SURVEYORS ROD.

Application filed May 3, 1917.

To all whom it may concern."

Be it known that I, CHARLES LoGAsA, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Surveyors Rods, of which the following is a specification.

This invention relates to geometrical instrument's and particularly to surveyors rods.

The primary feature of invention is the provision of a simple folding rodwhich shall be cheap to manufacture, rigid and of accurate length when extended, and compact when folded.

Such rods are available for use with various of the markings in common use by engineers, but are peculiarly suited to use as stadia rods. In this connection I illustrate a novel stadia marking having certain inherent advantages contributing to sharpness and clearness, and hence suited for use in sectional or jointed rods, which, like the one illustrated herein, have surface projections. Such markings may, however, be used on any conventional type of rod.

In the drawings 2-- Figure 1 is a front elevation of the rod extended;

Fig. 2 is an edge view thereof, the folded position being indicated in dotted lines;

Fig. 3 is an enlarged perspective view of a joint with the locking block removed; and

Fig. 4 is a View similar to Fig. 3, showing a modified construction.

The twelve-foot rod illustrated in the drawings is composed of three four-foot sections 5, 6, 7 reversely hinged together at 8 and 9. The hinges 8 and 9 are of the wide, strap variety and extend the full width of the rod and for a considerable distance along it on each side of the joint. The hinges are held by rivets headed down over washers so that a permanent and positive fastening is secured. This is necessary because the sections should abut closely when extended thus subjecting the hinges to considerable stress in addition to that exerted by the wedge locking blocks used to hold the rod extended.

At opposite sides of each joint and on the Specification of Letters Patent.

Patented Dec. at, 191?... Serial No. 166,144.

face of the rod away from the corresponding hinge, each of the two sections abutting at such joint is provided with an overhanginglug 10. Each pair of lugs 10 receives between their opposed overhanging faces 11 a lockingwedge block 12 whose ends 13 are beveled to fit the overhanging faces 11 of the lugs 10 and exert a double wedging action thereagainst as the block is forced laterally under the lugs. Such wedging action tends to force the lugs 10 apart while forcing block 12 into face engagement with the sections of the rod at the joint, and is secured by inclining the contacting surfaces 11 and 13 with respect to both the transverse dimensions of the rod. Differently stated the contacting plane faces 11 and 13 do not make a right dihedral angle with either the face or the edge of the rod.

The lugs 10 and block 12 are made of any hard close-grained wood or may be of metal and the lugs 10 are held by rivets headed down over washers. The lugs 10 are beveled at 14 to prevent the casting of shadows so far as possible.

When the rod is folded the lugs 10 prevent the sections 5, 6 and 7 from entering into close contact and the resulting spaces are sufficient to receive the blocks 12. The folded rod thus makes a close package onethird the length of the rod and something over four times its thickness. As the length is the most troublesome dimension the freedom from end projections is of marked advantage.

In some cases to secure greater strength the construction is modified as shown in Fig.

4. Here the form is unchanged except that the face of the block 12 is notched out as at 15 to receive over-hanging fingers or lug extensions 16 formed on the lugs 10. The wedging faces 13 are retained and are identical in form and function with the faces 13 of the type of wedge block first described. The extensions 16, however, give additional strength. a 1

The stadia marking which I have adopted for use with this rod has certain advantages for use in sectional rods because the limits of each foot interval are marked by the edge of a bold transverse index. The coincidence of these edges with the ends of the sections makes possible accurate marking on such projecting parts as hinge lugs, locking lugs, etc., whose presence is incident to the jointed construction.

Assuming for example a White rod with black markings, two individual markings are used on the alternate one-foot intervals to indicate foot divisions. Either marking may be used for the even-numbered intervals and the other for the odd.

The marking of foot divisions on the even-numbered foot intervals in the rod illustrated consists of four approximately equilateral triangles 17 whose bases are al'ined in corner contact and are foot in length, A clear While interval 18, foot long exists between each end of the series of four triangles and the limits of the one foot interval. The apices of the triangles thus markeven numbered one-tenth foot intervals and the base corners mark the odd numbered one tenth foot intervals on the rod. The black triangles being of limited altitude extend only part way across the face of the r d- 7 The marking of foot divisions on the odd numbered foot intervals similarly includes fo'urblack triangles 19 whose bases M9 /5 fOOt and whose apices and base corners mark the even numbered and odd numbered foot intervals respectively. These triangles are however, tall isosceles trian- 'gles extending preferably the full width of the rod as sllbWn and thus distinguishable from the triangular markings of even numbered one foot intervals. The foot intervals between each end of the series of triangles and the limits of the one foot interval are marked by a black band 20 tapered sharply at 21 to form an index point better defining the end of the foot interval. Thus alternate foot intervals are sharply distinguished, and the line of division between them a centuat Od a tenths are similarly indicated throughout the length ofthe rod, and all markings are favorab e to rea y s li of h telescope crqs'sha rsnithpugh I have described the construction and dimensions with some particularity definitelirnitations are not implied'thereby. I have ,describedlone standard embodiment of the invention and modifications of form and dimension will readily suggest themselves the light thereof. Such modificatpns are eei t mplefisd nd f Within h scope of my invention except as excluded by the terms of the claims.

Havin thus described my invention, what I claim is 1. A surveyors rod comprising in combination two or more rod sections adapted to aline end to end to form a continuous rod; hinges connecting adjacent sections, the pivots of each hinge lying approximately in the plane of a face of the rod; a pair of lugs for each hinge, each such pair being on the opposite face of the rod from its hinge, one lug on each of the abutting rod sections, and each lug having an over-hangin face oblique to the face and to the edge of the rod; and \vedging blocks one for each joint in the rod and adapted to abut against the face of the rod and having \vedging end surfaces adapted to engage the over-hanging faces of said lugs.

2. A surveyors rod comprising in combination two or more rod sections adapted to aline end to end to form a continuous rod; hinges connecting adjacent sections, the pivots'of each hinge lying approximately in the plane of a face of the rod; a pair of lugs for each hinge, each such pair being on the opposite face of the rod from its hinge, one lug on each of the abutting rod sections, and each lug having an over-hanging face oblique to the face and to the edge of the rod, and a finger or extension projecting beyond said overhanging face; and wedging blocks, one for each joint in the rod, cut away to receive and fit beneath said fingers or. projections on said lugs, and having wedging end surfaces adapted to engage the overhanging faces of said lugs.

3. A stadia rod divided into unit intervals and tenths thereof by marking in contrasting colors, the odd numbered tenths of each unit interval being indicated by the base corners of four equal colored triangles arranged with their bases alined in corner contact, and the even numbered tenths being marked by the apices of said triangles, the altitude of such triangles in the odd numbered unit intervals being different from the altitude of such triangles in the even numbered unit intervals, the terminal one-tenth intervals of alternate unit intervals being marked by a horizontal colored band equal in vertical dimension to the one-tenth interval.

In testimony whereof I have signed my name to this specification.

CHARLES LOG/ASA.

Qantas of patentmay he obtained for five cents each, by addressing the Commissioner of latents, z Washingtgn, I1. 61 

